Device for preparing food

ABSTRACT

The invention relates to a device for preparing food, such as a grilling or baking device, comprising a unit for heating air ( 5 ) and possibly a rack. Above the unit for heating air ( 5 ) several run-off grooves ( 11 ) for the juices of the food being prepared are arranged at a distance from each other and preferably in the same plane. Between the device for heating the air ( 5 ) and the run-off grooves ( 11 ) at least one device ( 28 ) is positioned for deflecting the heated air which rises from the air-heating device in the direction of the run-off grooves.

BACKGROUND OF THE INVENTION

The invention relates to an apparatus for preparing food, such as agrilling or baking device, comprising a device for heating the air andoptionally a grill. Above the unit for heating air, hollow profiles arearranged which can be flowed through by a coolant and whose upper sidesare provided with a groove-like arrangement and form run-off grooves forthe juices of the food being prepared.

In previously known apparatuses of this kind, the coolant flowingthrough the hollow profiles, which helps avoid any overheating and theresulting charring of the juices of the food, is either not moved, as aresult of which only a low cooling effect is obtained, or there is aforced movement by the hollow profiles which depends on an externalenergy source such as a battery-operated coolant pump. The latter leadsto the consequence that the preparing apparatus will only functioncorrectly when suitable batteries or at least a mains connection areavailable. Moreover, the installation of a coolant pump leads toadditional efforts in production and maintenance.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide anapparatus of the kind mentioned above in which a forced movement of thecoolant can be realized without any external energy source.

This is achieved in accordance with the invention in that the hollowspace within the hollow profiles are formed by at least one, preferablytwo, chamber(s) which extend continuously in the longitudinal directionof the hollow profiles, whereby the chamber(s) are or can be flowedthrough by a coolant by means of at least one apparatus to form acoolant flow by using a pressure difference produced in the preparingapparatus.

In this way one or several chambers of the hollow profiles can be flowedthrough by the coolant without requiring any dependence on any externalenergy source. The production and maintenance of an apparatus inaccordance with the invention is also simplified by the fact that acoolant moving apparatus which is operated by an external energy sourcecan be omitted. The apparatus for forming the coolant flow produces acoolant movement by way of a pressure difference which is produced forexample as a result of combustion, a difference in height, difference indensity or the like, so that the energies converted in the preparingapparatus for heating for example are used not only for heating the foodto be prepared.

A particularly advantageous embodiment of the invention provides thatthe coolant is a gas, preferably air. As a result, the air sucked infrom the ambient environment can be used as a coolant.

A particularly efficient apparatus for forming a coolant flow can beachieved according to a variant of the invention by a suction draftapparatus which allows a relatively strong coolant movement.

It may be provided for in a further embodiment of the invention that thesuction draft apparatus is formed by a suction opening of the heatingdevice, that the chamber, or one thereof, of the hollow profiles is inconnection at a face-side end with the suction opening via a connectingconduit, and that the opposite other face side of the chamber(s) isopen.

Every heating device produces an air movement by the heat emitted by thesame. Particularly the suction draft produced during combustion,produces an air flow towards the source of combustion. This suctioneffect produced during the combustion can therefore also be used for thesuction draft effect through the hollow profiles. Moreover, during thesupply of a gaseous fuel, the negative pressure produced around the fuelflow can be applied to the coolant movement.

It may be provided in a further embodiment of the invention that theheating device consists of several, preferably rod-shaped gas burnerswhose gas supply lines extend through the associated connectingconduits, with the air suction opening being disposed within theconnecting conduit in the gas supply line.

The gas burners allow a planar heating of the food to be preparedwithout producing any disturbing combustion exhaust gases.

The gas burner can be provided with gas outlet nozzles which are spacedfrom one another along the length of the burner, so that gas combustionis obtained which is evenly distributed over the length of the gasburner and an even heating of the food to be prepared is achieved.

In order to prevent any dripping of juices from the food to be preparedonto the gas burner, it can be provided in accordance with a furtherembodiment of the invention that the rod-shaped gas burners extendparallel to the hollow profiles.

It can be provided according to a further variant of the invention thatthe suction draft apparatus is formed by an upwardly extending (in theused position) chimney-like flue conduit, that the chambers, or onethereof, of the hollow profiles are connected with the flue conduit attheir face-sided end, which flue conduit is open at its upper end, andthat the opposite other face-sided end of the chamber(s) is open.

In this way it is possible to use the difference in height between theair inlet position at the hollow profile ends and the upper end of theflue conduit in order to produce a respective suction draft effect onthe air flowing through the hollow profiles.

In order to provide a further increase in the flue draft it may beprovided according to a further embodiment of the invention that thechimney-like flue conduit is provided with laterally provided air inletslots. In this way, the warm air of low density which rises from theheating device can enter the flue conduit and reinforce the suctiondraft acting on the air flowing through the hollow profile chambers.

A preferable further development of the invention provides that thechimney-like flue conduit is provided with a rectangular cross section.

A particularly even distribution of the warm air rising from the heatingdevice can be achieved according to a further variant of the inventionin such a way that the hollow profiles, as seen in the used position,are arranged horizontally and the run-off grooves are arranged inclinedagainst the horizontal.

In can be provided for in a further embodiment of the invention that thechamber(s) is or are additionally connected with an apparatus for forcedcooling, e.g. an air fan, a coolant pump, or the like. A forced coolingcan be achieved in addition to the coolant flow produced by the pressuredifference, which forced cooling can be activated in the case ofinsufficient cooling performance.

Hollow profiles which are easy to produce in a constructional sense andare used to connect with the suction draft apparatus can be achieved insuch a way that the two chambers are provided with a superimposedarrangement.

According to a further variant of the invention it can be provided thatthe heating device is formed by a combustion chamber for filling withcharcoal and the suction opening by an air supply opening for theprimary air supply into the combustion chamber for the combustion of thecharcoal.

The air sucked in from the outside during the combustion of the charcoalflows first through the hollow profiles and thus achieves a measurablereduction in the temperature of the food to be prepared.

The invention relates further to an apparatus for preparing food such asa grilling or baking device, comprising a device for heating air andoptionally a grill. Above the device for heating the air several run-offgrooves for the juices of the food being prepared are arranged at adistance from one another and preferably in one plane.

Run-off grooves for devices such as grills and baking ovens have longbeen used to collect the juices of food being prepared and to dischargethe same so as to prevent them from reaching the heating device andburning there, as otherwise the vapors produced during the combustioncould contaminate the food being prepared with carcinogenic substances.

The run-off grooves are located directly above the heating device andtherefore require additional cooling since the juices running off on thegrooves could otherwise be overheated and would thus contribute to theproduction of amounts of carcinogenic substance.

Most of the known cooling apparatuses which are used for this purposeare provided with a very complex arrangement and require a forcedmovement of the coolant.

It is therefore the object of the present invention to provide anapparatus of the kind mentioned above with which in a technically simpleway it is possible to avoid any overheating of the food juices drippingonto the run-off grooves.

This is achieved in accordance with the invention in such a way thatbetween the device for heating the air and the run-off grooves at leastone apparatus for deflecting the heated air rising from the device forheating in the direction of the run-off grooves.

As a result, the portions of the rising heated air which would otherwisecome directly into heat contact with the run-off grooves and would heatthe same are conducted away from the run-off grooves and between thesame. As a result of the deflection of the heat flow it is possible toomit any direct cooling of the run-off grooves, or at least anyovertemperatures that might occur on the run-off grooves will be so lowthat the same can be reduced with very simple cooling measures.Moreover, it is possible to prevent with the horizontal arrangement ofthe deflection apparatus with an inclined arrangement of the hollowprofiles that the rising heated air is conducted upwardly along thehollow profiles and that as a result a much stronger heating occurs atthe highest position of the hollow profiles than at the positions of theinclined hollow profiles which are beneath the same. An averaging of thetemperature progress is thus achieved, so that the food being preparedis not heated with differing intensities.

It can be provided for in a further embodiment of the invention that theapparatus for deflecting the heated air is formed by profiled sheetmetal extending parallel to the longitudinal direction of the run-offgrooves and beneath the same.

The profiled sheets are thus arranged directly between the heatingdevice and the run-off grooves and deflect the rising hot air away fromthe lower side of the run-off grooves, so that the same can progress onits way to the food being prepared between the mutually spaced run-offgrooves.

It can be provided for in accordance with a further embodiment of theinvention that the profiled sheets are arranged, as seen in across-sectional view, in the shape of a semi-ellipse divided along itsmain axis, with the concave portion of the semi-ellipse facing therun-off grooves.

The profile sheet thus provided with a streamlined arrangement allows ahighly efficient deflection of the heated air rising from the heatingdevice.

In order to achieve the most comprehensive deflection of the risingheated air, the profiled sheets can extend, as seen in a cross-sectionalview, at least over the entire width of the run-off grooves.

As has already been mentioned above, the deflection apparatus allowskeeping the rising heated air at least partially away from the run-offgrooves and thus achieving a measurable reduction of the groovetemperature. In order to achieve an additional cooling it can beprovided according to a further embodiment of the invention that hollowprofiles which can be flowed through by a coolant such as air or waterare arranged on the lower side of the run-off grooves. The coolant thatcan be conducted through the hollow profiles ensures that a relativelylow run-off groove temperature can be maintained, even during anyoperation of the preparation apparatus in accordance with the inventionover prolonged periods of time.

In a particularly advantageous embodiment of the invention it can beprovided that the hollow profiles each consist of a basic profile madeof floor walls which are arranged V-shaped (as seen in a cross-sectionalview) and laterally adjoining vertical walls, and that the run-offgrooves having a V-shaped cross section are placed on the vertical wallsof the basic profile.

When the hollow profiles are formed according to a further embodiment ofthe invention of a heat insulating material, a further reduction of thetemperature prevailing on the run-off groove is achieved.

In a further embodiment of the invention the heat insulating materialcan be formed of a ceramic fiber material which is provided with aparticularly low thermal conductivity.

To prevent any particles from the rough or fibrous surface of the hollowprofiles from reaching the food being prepared, the hollow profiles canbe completely encased, with the encasing preferably being formed atleast partially by a metal or metal alloy, enamel, glass or a glassmixture, or any temperature-resistant plastic such as teflon or thelike.

In order to achieve an effective coolant movement, the hollow profilewith the inserted run-off grooves can be in connection at one face-sidedend via a connecting conduit with an apparatus for forming a coolantflow by utilizing a pressure difference produced in the preparationapparatus, preferably a suction draft apparatus, and the opposite otherface-sided end can be open.

External energy sources for the coolant movement can be omitted as aresult of the apparatus used thereby for forming a coolant flow.

It can be provided in accordance with a further embodiment of theinvention that the heating device is formed by several, preferablyrod-shaped, gas burners whose gas supply lines extend through theassociated connecting conduits, with an air-suction opening beingprovided within the connecting conduit forming the suction draftapparatus in the gas supply line.

The gas flowing into the heating device sucks in air by way of theair-suction opening of the gas supply line and thereby produces an airstream which is conducted through the hollow profiles and causes acooling of the same there.

In a further embodiment of the invention the gas burners can be providedwith gas outlet nozzles which are mutually spaced from one another overits length, thus ensuring a very even emission of gas over the entirelength of the gas burner.

A particularly preferable distribution of heat can be achieved with thegas burners in the case when the rod-shaped gas burners extend parallelto the hollow profiles and run-off grooves in accordance with a furtherembodiment of the invention.

A further variant of the invention can be that the heating device isformed by a combustion chamber for filling with charcoal and theapparatus for providing the coolant flow is formed by an air supplyopening into the combustion chamber. The air sucked in from the outsideduring the combustion of the charcoal first flows through the hollowprofiles and achieves in this process a measurable reduction of thetemperature of the food being prepared.

For the purpose of a simpler production of the hollow profiles thehollow profiles can be arranged in two parts in accordance with afurther embodiment of the invention.

It can be provided according to a further embodiment of the inventionthat the hollow profiles are each formed by a basic profile consistingof, as seen in a cross-sectional view, two mutually spaced traverseshaving a V-shaped cross section and two laterally adjoining verticalwalls, as well as a run-off groove having a V-shaped cross section whichis placed on the walls of the basic profile.

In this way the hollow profiles which are subdivided in the manner ofchambers can be produced in a simple way. The run-off groove can be madeof a different material, so that the same especially enables a favorableheat contact between the cooling air and the juices of the food beingprepared.

In order to prevent the hot air rising from the heating device fromoverheating the hollow profiles, the hollow profiles can be made of aheat insulating material.

In a further embodiment of the invention the heat insulating materialcan be formed of a ceramic fiber material which is provided with aparticularly low thermal conductivity.

To prevent any particles from the rough or fibrous surface of the hollowprofiles from reaching the food being prepared, the hollow profiles canbe completely encased, with the encasing preferably being formed atleast partially by a metal or metal alloy, enamel, glass or a glassmixture, or any temperature-resistant plastic such as teflon or thelike.

In order to achieve an effective coolant movement, the hollow profileswith the inserted run-off grooves can be in connection at one face-sidedend via a connecting conduit with an apparatus for forming a coolantflow by utilizing a pressure difference produced in the preparationapparatus, preferably a suction draft apparatus, and the opposite otherface-sided end can be open.

BRIEF DESCRIPTION OF THE DRAWING

The invention is now explained in closer detail by reference to theembodiment shown in the drawings, wherein:

FIG. 1 shows an embodiment of the apparatus in accordance with theinvention in an oblique view;

FIG. 2 shows a sectional view AA through the apparatus according to FIG.1;

FIG. 3 shows a sectional view BB through the apparatus according to FIG.1;

FIG. 4 shows a sectional view CC through the apparatus according to FIG.1;

FIG. 5 shows a further embodiment of the apparatus in accordance withthe invention in an oblique view;

FIG. 6 shows a sectional view AA through the apparatus according to FIG.5; and

FIG. 7 shows a sectional view BB through the apparatus according to FIG.5;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows the parts of an apparatus for preparing food such as agrilling or baking device in an oblique view, comprising a device forheating air 5 which is formed in this embodiment by several rod-shapedgas burners 5, of which one is shown in FIG. 1.

The device for heating the air can also be suitable for burning solidfuels. A grill can be provided on which charcoal can be burnt.

Hollow profiles or section members 11, 12 are arranged above the devicefor heating the air, which hollow profiles are flowed through by acoolant and whose upper sides are provided with a groove-likearrangement and thus form run-off grooves 11 for the juices of the foodbeing prepared.

The hollow profiles are arranged horizontally as seen in the position ofuse, and the run-off grooves 11 are provided with an arrangementinclined against the horizontal. Draining edges are provided at thelongitudinal sides of the run-off grooves which prevent any lateraldripping onto the air heating device.

The rod-shaped gas burners 5 are provided along their length withmutually spaced gas outlet nozzles 3 and extend parallel to the hollowprofiles 12,11.

It is now provided in accordance with the invention that the hollowspace within the hollow profiles 11, 12 is formed by at least onechamber, with there being two chambers 1, 2 in FIG. 1 which extendcontinuously in the longitudinal direction of the hollow profiles 11,12. The chambers 1, (FIG. 2) can be flowed through by coolant by meansof an apparatus to produce a coolant flow 7, 19 by using a pressuredifference of coolant produced in the preparation apparatus. Saidcoolant flow apparatus is formed in the shown embodiment by two suctiondraft apparatuses 7, 19. It is also possible to use instead of saidapparatuses a flow apparatus which is based on pressure instead of onsuction draft.

Preferably, a gas, and air especially, can be used as coolant. It isalso possible to use a liquid such as water for cooling the hollowprofiles.

The food to be prepared on the apparatus in accordance with theinvention produces juices during its heating which would drip onto theheating device and would produce carcinogenic substances there. For thispurpose, V-shaped run-off grooves 11 are arranged on the hollow profiles12 which collect the dripping juice and carry off the same in thelongitudinal direction. To ensure that the hollow profiles per se arenot heated to a temperature which would overheat the juices of the foodbeing prepared, they can be flowed through by a coolant which reducesthe hollow profile temperature to such an extent that the juices willnot char.

The cooling function of the two chambers 1, 2 is shown with particularclarity in FIG. 2. Chamber 1 which extends below chamber 2 is inconnection at one face-sided end via a connecting conduit 6 with thesuction draft apparatus which is arranged as a suction opening 19, withthe other end of the chamber 1 which is opposite to the one end beingprovided with an open arrangement, so that air from the ambientenvironment can be sucked in through said open end. Chamber 1 is fullysufficient for a lower cooling effect, so that chamber 2 could also beomitted. The suction effect of the suction opening 19 is obtained fromthe gas stream which is conducted into the rod-shaped burner 5 via thegas supply line 10 which is guided through the connecting conduit 6. Asa result of the negative pressure formed at the suction opening 19, anair stream indicated by arrows 30 is produced which mixes with the gasstream in the suction opening 19 which is arranged in the gas supplyline 10 and thus provides the oxygen required for a favorablecombustion. The air stream 30 simultaneously produces the cooling of thehollow profiles 11, 12, because air originating from the ambientenvironment is pulled through the lower chamber 1 and thus cools thehollow profiles 11, 12.

In order to further increase the cooling effect, a further chamber 2 isprovided in the embodiment according to FIG. 1 through which thesimilarly cool ambient air can be conducted through the hollow profiles11, 12. Chamber 2 can also be operated alone by omitting chamber 1.

The suction draft apparatus is formed (in the position of use) by achimney-like, upwardly extending flue conduit 7 which is connected withchamber 2 at its face-sided end. The chamber 2 is open at its otheropposite end. Said open end can be used to suck in cool ambient airthrough the chamber 2 of the hollow profile and be conducted through thesame. The suction effect is produced from the pressure difference whichis obtained by the chimney height. The higher the chimney-like conduit 7extends upwardly, the stronger the intake of air.

In order to increase the suction effect, the chimney-like flue conduit 7with a rectangular cross section is provided with laterally applied airinlet slots 8, 9 through which the hot air rising from the heatingdevice reaches the flue conduit, which as a result of its low specificdensity also produces a suction effect on the air stream 40 arrivingfrom chamber 2.

Chamber 2, or also both chambers 1, 2, can be additionally be connectedwith an apparatus for forced cooling (not shown) such as an air fan, acoolant pump, or the like. A forced cooling can be achieved in additionto the coolant flow produced by the pressure difference, which forcedcooling can be activated in the case of inadequate cooling performance.

Instead of the gas burner it is also possible to use conventionalcharcoal burning or any similar burning for heating the food to beprepared. The heating device can consist of a combustion chamber forfilling with charcoal and the suction opening by an air supply openingfor the primary air supply into the combustion chamber for thecombustion of the charcoal. Once the combustion process begins, air issucked in by way of the air inlet opening which flows first through thehollow profiles and cools the same.

The embodiment according to FIGS. 1 through 4 shows two superimposedchambers 1, 2 which are arranged within the hollow profiles. As hasalready been mentioned above, there could also be only one or evenseveral chambers of this kind.

As is shown in FIG. 3, the hollow profiles 12, 11 are provided in anarrangement consisting of two parts.

The hollow profiles are each formed by a basic profile 12 consisting of,as seen in a cross-sectional view, two mutually spaced traverses 24, 25having a V-shaped cross section and two laterally adjoining verticalwalls 22, 23, as well as a run-off groove 11 having a V-shaped crosssection which is placed on the walls 22, 23 of the basic profile 12. Therun-off groove 11 covers the upper part of the basic profile in such away that the upper chamber 2 is closed. The chambers 1, 2 can also bearranged in any other way. The hollow profiles 11, 12 can be formed froma heat insulating material, so that heat emitted by radiation orconvection is held off from the interior of the hollow profiles 11, 12.

As a result, the high temperatures in the range of 400° C. to 650° C.which prevail on the lower side of the hollow profiles 12 cannotpenetrate up to the run-off grooves 11, so that the juices of the foodbeing prepared only come into contact with surfaces of a temperature ofless than 120° C. and the charring thereof is prevented.

The heat insulating material is preferably formed by a ceramic fibermaterial which has a thermal conductivity for example in the range of0.08 W/mK at 400° C. up to 0.23 W/mK at 1000° C. These values arefulfilled by a ceramic fiber material which can be obtained under thedesignation Form 612™ which contains high-temperature-resistant glassfibers containing ZrO₂, CaO, MgO, SiO₂, and Al₂O₃. It is also possibleto use any other suitable heat insulating material to form the hollowprofiles.

In order to line the rough surface of the heat insulating material tothus improve the hygienic conditions, a complete encasing of the hollowprofiles can be provided which is formed, as required, by a metal or ametal alloy, an enamel layer or a glass or glass mixture. A furtherpossibility for encasing the ceramic fiber material is to usetemperature-stable plastic materials such as teflon or the like. Theencasing contributes to the thermal conductivity and should therefore bechosen as thin as possible, e.g. some 100 μm.

FIG. 5 shows in an oblique view parts of a further embodiment of theapparatus in accordance with the invention for preparing food such as agrilling or baking device, comprising a device for heating air 5, whichin this case is formed by several rod-shaped gas burners 5 of which oneis shown in FIG. 5.

The device for heating the air can also be suitable for burning solidfuels. A grill can be provided on which charcoal can be burnt.

In accordance with the invention, an apparatus 28 for deflecting the airheated by the device 5 and rising in the direction towards the run-offgrooves 11 is arranged between the device for heating the air 5 and therun-off grooves 11. The deflection of the air rising from the burners 5can be performed in numerous ways and various different means, as areknown to the man skilled in the art of flow techniques. The hot air mustbe prevented in any case from coming into contact with the run-offgrooves 11 and heating the same to a temperature which could lead to theincineration or charring of the juices from the food being prepared.

The food to be prepared on the apparatus in accordance with theinvention produces juices during its heating which would drip onto theheating device and would produce carcinogenic substances there. For thispurpose, V-shaped run-off grooves 11 are arranged on the hollow profiles12 which collect the dripping juice and carry off the same in thelongitudinal direction. To ensure that the hollow profiles per se arenot heated to a temperature which would overheat the juices of the foodbeing prepared, they can be flowed through by a coolant which reducesthe hollow profile temperature to such an extent that the juices willnot char.

In addition to the deflection of the heated rising air, hollow profiles12 which can be flowed through by a coolant are arranged on the lowerside of the run-off grooves 11, which hollow profiles help prevent thatthe run-off grooves can become too hot during a longer period ofoperation of the apparatus in accordance with the invention. Therod-shaped gas burners 5 are provided with gas outlet nozzles 3 whichare spaced from one another along the length thereof and extend parallelto the hollow profiles 12.

The reduction of the temperature shall occur to such an extent that thejuices which drip onto the run-off groove will not char and producecarcinogenic particles which could then contaminate the food beingprepared.

Preferably, a gas, and air especially, is used as coolant. It is alsopossible to use a liquid such as water to cool the hollow profiles.

The apparatus for deflecting the heated air is formed pursuant to FIGS.5 to 7 by profiled sheets 28 which extend parallel to the longitudinaldirection of the run-off grooves beneath the same and which arepreferably formed of a stainless steel. The profiled sheets 28 arearranged, as seen in a cross-sectional view, in the shape of asemi-ellipse divided along its main axis, with the concave portion ofthe semi-ellipse facing the run-off grooves 11 (FIG. 7).

The profiled sheets 28 extend, as seen in the cross-sectional view, overthe entire width of the run-off grooves 11 and even extend beyond thesame in order to effectively keep the rising air away from the run-offgrooves 11.

The hollow profiles as shown in FIGS. 5 to 7 are each formed by a basicprofile 12 consisting of, as seen in a cross-sectional view, two floorwalls 24, 25 having a V-shaped cross section and two laterally adjoiningvertical walls 22, 23, with the run-off grooves 11 having a V-shapedcross section being placed on the vertical walls 22, 23 of the basicprofile 12.

The hollow profiles 12 are preferably formed of a heat insulatingmaterial, so that a further conduction of the heat emitted to the hollowprofiles to the run-off grooves 11 will occur only to a marginal extent.As a result, the high temperatures in the range of 400° C. to 650° C.which prevail on the lower side of the hollow profiles 12 are kept offthe run-off grooves 11, so that the juices of the food being preparedonly come into contact with surfaces of a temperature of less than 120°C. and the charring thereof is prevented.

The heat insulating material is preferably formed by a ceramic fibermaterial which has a thermal conductivity for example in the range of0.08 W/mK at 400° C. up to 0.23 W/mK at 1000° C. These values arefulfilled by a ceramic fiber material which can be obtained under thedesignation Form 612™ which contains high-temperature-resistant glassfibers containing ZrO₂, CaO, MgO, SiO₂, and Al₂O₃. It is also possibleto use any other suitable heat insulating material to form the hollowprofiles.

In order to line the rough surface of the heat insulating material tothus improve the hygienic conditions, a complete encasing of the hollowprofiles can be provided which is formed, as required, by a metal or ametal alloy, an enamel layer or a glass or glass mixture. A furtherpossibility for encasing the ceramic fiber material is to usetemperature-stable plastic materials such as teflon or the like. Theencasing contributes to the thermal conductivity and should therefore bechosen as thin as possible, e.g. some 100 μm.

As shown in particular in FIG. 6, the hollow profiles 12 are used forconducting air in order to allow an additional cooling of the run-offgrooves 11.

For this purpose and according to the embodiment in accordance withFIGS. 1 to 4, the hollow profiles 12 are in connection with the insertedrun-off grooves 11 at a face-sided end via one connecting conduit 6 eachwith the suction draft apparatus 19, whereas the respective otheropposite face-sided end is open.

Instead of the gas burners it is also possible to use conventionalcharcoal combustion or any similar combustion to heat the food to beprepared. The heating device can be formed by a combustion chamber forfilling with charcoal and the apparatus to form the coolant flow by anair supply opening into the combustion chamber.

What is claimed is:
 1. Apparatus for preparing food, comprising: aheater for heating air; at least one hollow section member defining alongitudinal axis and arranged above the heater, wherein the hollowsection member has an upper side, formed with a groove for providing arun-off for juices of a food being prepared, and includes at least onechamber extending continuously in a direction of the longitudinal axis;and means interacting with the hollow section member for circulating acoolant through the chamber through exploitation of a pressuredifferential prevailing in the apparatus for preparing food, wherein thehollow section member has two of such chamber.
 2. The apparatus of claim1, wherein the coolant is a gas.
 3. The apparatus of claim 2, whereinthe coolant is air.
 4. The apparatus of claim 1, wherein the means forcirculating the coolant includes a suction draft unit.
 5. The apparatusof claim 1, and further comprising a cooling means, connected to thechamber, for effecting a forced cooling action.
 6. The apparatus ofclaim 5, wherein the cooling means is selected from the group consistingof air fan and a coolant pump.
 7. The apparatus of claim 1, wherein thehollow section member is horizontal and the run-off is arranged at aninclination to the horizontal.
 8. The apparatus of claim 1, wherein thetwo chambers are arranged in superimposed disposition.
 9. Apparatus forpreparing food, comprising: a heater for heating air; at least onehollow section member defining a longitudinal axis and arranged abovethe heater, wherein the hollow section member has an upper side, formedwith a groove for providing a run-off for juices of a food beingprepared, and includes at least one chamber extending continuously in adirection of the longitudinal axis; and means interacting with thehollow section member for circulating a coolant through the chamberthrough exploitation of a pressure differential prevailing in theapparatus for preparing food, wherein the means for circulating thecoolant includes a suction draft unit which includes a suction conduitconnected to a suction opening of the heater, wherein the chamber hasone end connected to the suction conduit and another end, which is open.10. The apparatus of claim 9, wherein the heater includes at least onegas burner having a gas supply line extending through the suctionconduit, wherein the suction opening of the heater is disposed in thegas supply line within the suction conduit.
 11. The apparatus of claim10, wherein the gas burner has a rod-shaped configuration.
 12. Theapparatus of claim 10, wherein the gas burner has an axial length and isprovided with gas outlet nozzles in spaced-apart relationship along theaxial length.
 13. The apparatus of claim 10, wherein the gas burnerextends in parallel relationship to the hollow section member.
 14. Theapparatus of claim 9, wherein the heater has a combustion chamber forfilling with charcoal, wherein the suction opening is an air supplyopening for primary air supply into the combustion chamber forcombustion of the charcoal.
 15. Apparatus for preparing food,comprising: a heater for heating air; at least one hollow section memberdefining a longitudinal axis and arranged above the heater, wherein thehollow section member has an upper side, formed with a groove forproviding a run-off for juices of a food being prepared, and includes atleast one chamber extending continuously in a direction of thelongitudinal axis; and means interacting with the hollow section memberfor circulating a coolant through the chamber through exploitation of apressure differential prevailing in the apparatus for preparing food,wherein the means for circulating the coolant includes a the suctiondraft unit which includes an upwardly extending chimney-like flueconduit, wherein the chamber has one end connected to the flue conduitand another end, which is open, wherein the flue conduit has an openupper end.
 16. The apparatus of claim 15, wherein the flue conduit haslateral air inlet slots.
 17. The apparatus of claim 15, wherein the flueconduit has a rectangular cross section.
 18. Apparatus for preparingfood, comprising: a heater for heating air; a run-off for drainingjuices of a food being prepared; a baffle, arranged between the heaterand the run-off, for deflecting heated air rising from the heater in thedirection towards the run-off; and at least one hollow section member,positioned at a lower side of the run-off, for passage of a coolant. 19.The apparatus of claim 18, wherein a plurality of such run-off extendsin a common plane.
 20. The apparatus of claim 18, wherein the baffle isformed by a profiled sheet extending in parallel relationship to andbeneath the run-off.
 21. The apparatus of claim 20, wherein the profiledsheet is arranged, as seen in a cross-sectional view, in the shape of asemi-ellipse divided along its main axis and defining a concave portionfacing the run-off.
 22. The apparatus of claim 20, wherein the profiledsheet extends, as seen in a cross-sectional view, at least over anentire width of the run-off.
 23. The apparatus of claim 18, wherein thecoolant is one of air and water.
 24. The apparatus of claim 18, whereinthe hollow section member has a basic body having V-shaped bottom wallsand lateral vertical walls interconnecting the bottom walls, wherein therun-off have a V-shaped cross section and are placed on the verticalwalls of the basic body.
 25. The apparatus of claim 18, wherein thehollow section member is formed by a heat insulating material.
 26. Theapparatus of claim 25, wherein the heat insulating material is made froma ceramic fiber material.
 27. The apparatus of claim 18, and furthercomprising an enclosure for completely encasing the hollow sectionmember, wherein the enclosure is made, at least partially, of a materialselected from the group consisting of metal, metal alloy, enamel, glass,glass mixture, and any temperature-resistant plastic.
 28. The apparatusof claim 27, wherein the enclosure is made of teflon.
 29. The apparatusof claim 18, and further comprising means interacting with the hollowsection member for circulating the coolant through the hollow sectionmember through exploitation of a pressure differential prevailing in theapparatus for preparing food; and a suction conduit for connecting oneend of the hollow section member to the means for circulating thecoolant, wherein the hollow section member has another end which isopen.
 30. The apparatus of claim 29, wherein the means for circulatingthe coolant includes a suction draft unit.
 31. The apparatus of claim30, wherein the heater includes at least one gas burner having a gassupply line extending through the suction conduit and having a suctionopening disposed in the suction conduit and defining the suction draftunit.
 32. The apparatus of claim 31, wherein the gas burner has arod-shaped configuration.
 33. The apparatus of claim 31, wherein the gasburner has an axial length and is provided with gas outlet nozzles inspaced-apart relationship along the axial length.
 34. The apparatus ofclaim 33, wherein the gas burner extends in parallel relationship to thehollow section member and the run-off.
 35. The apparatus of claim 33,wherein the heater includes a combustion chamber for filling withcharcoal and the means for circulating the coolant is formed by an airsupply opening into the combustion chamber.
 36. The apparatus of claim18, wherein the hollow section member is made of two parts.
 37. Theapparatus of claim 36, wherein the hollow section member includes abasic body having two V-shaped traverses in spaced-apart disposition andtwo lateral vertical walls connected to the traverses, wherein therun-off has a V-shaped cross section and is placed on the walls of thebasic body.